I am have a ton of issues and need help. I am essentially making a cover for a complicated part. Think of a silicone cover that protects a part. I have tried multiple ways of doing it however I can not figure it out. it is a Step file of the part so it has multiple radius. I started with extruding a box and not merging it. Combine (subtract) then tried to shell with the thickness I wanted the cover. I have had zero success. can anyone help???